This is a centered upside-down cannon. Not sure what you'd want to use it in, but here it is. Looks best on upside-down pipes.

IMPORTANT:
Due to the nature of this bug, you cannot edit anything while it is on or near the screen, or it will simply get put back on the grid. As a result, you have to finish the area you are placing it in before-hand.

Step 1:
Place a cannon (be it red or black) on top of a big muncher. It needs to be in a stack.

Step 2:
Move the ground you want the cannon on, over the cannon. In this example, I use a pipe. Choose the opposite direction you want it to fire in. Top right is going to be bottom left, and so on.

Step 3:
Place a big lava bubble directly over the muncher.

Step 4:
Drag the lava bubble far away from the cannon, and delete it. Return to the cannon, and voila!

Isn't this one of the steps to do the black whole glitch? Still looks good BTW, but I am just curious

Old 3DS XL info:
I used to have a 3DSafe A9LH V11.3.0-36U with Luma in my CTRNAND. Since ReiNAND Reibooted and Re-Reileased, I "switch"ed back.
Right now, I have boot9strap with Luma 8.0 as my CFW. Though, I'd like to see other CFW's for B9S.